A wire harness to be wired on a vehicle body is inserted into a resinous inner member-provided grommet mounted on a through-hole of a body panel. A portion of the wire harness inserted into the resinous inner member-provided grommet is protected, waterproofed, and protected against penetration of dust. FIG. 16A is an example of a conventional resinous inner member-provided grommet 1.
The resinous inner member-provided grommet 1 has a resinous inner member 3 accommodated inside a large-diameter cylindrical part 4. The cylindrical part 4 is continuous with a leading end of a small-diameter cylindrical part 5 of the body 7 of the grommet 2.
A locking flange part 3a of the resinous inner member 4 is fitted on an annular concavity 4a formed on the inner peripheral surface of the large-diameter cylindrical part 4. The periphery of a through-hole H of a body panel P is locked between a sealing lip 4b projected from an open end of the large-diameter cylindrical part 4 and a locking claw 3b of the resinous inner member 4.
In a normal state shown in FIG. 16A, the sealing lip 4b projects from the open end of the large-diameter cylindrical part 4. The lip 4b is pressed against the periphery of the through-hole H of the body panel P. Therefore, the resinous inner member-provided grommet 1 is capable of preventing penetration of water and dust.
However, when a pulling force is exerted on the large-diameter cylindrical part 4 toward the small-diameter cylindrical part 5, the locking force on the annular concavity 4a of the large-diameter cylindrical part 4 to the locking flange part 3a of the resinous inner member 3 becomes weak. As a result, the large-diameter cylindrical part 4 shifts in the direction shown with the arrow of FIG. 16B.
In association with the shift of the large-diameter cylindrical part 4, the sealing lip 4b shifts upward separating from the body panel P. Consequently water and dust may penetrate into the body 2 from a space S generated between the sealing lip 4b and the body panel P.
FIG. 17 is an example of a conventional resinous inner member-provided grommet 106.
The resinous inner member-provided grommet 106 has a resinous inner member 101 accommodated inside a large-diameter cylindrical part 107a of the body 107 of the grommet 106. A locking flange part 105 is fitted on an annular concavity formed on the inner peripheral surface of the large-diameter cylindrical part 107a. The periphery of a through-hole H1 of a body panel P is locked between a sealing lip 107b, projecting from an open end of the large-diameter cylindrical part 107a, and locking claws 102a-104a of the resinous inner member 101.
More specifically, of locking pieces 102-104 projecting from the peripheral wall of the resinous inner member 101, initially, locking claw 102a of the locking piece 102 is locked to the through-hole H1 of the body panel P. Then the side of the locking piece 102 opposite to the locking claw 102a is pressed into the through-hole H1. Thereafter, a locking claw 103a of the locking piece 103 at the side opposite to the locking claw 102a is inserted into and locked in the through-hole H1. In this manner, the grommet 106 is installed on the body panel P. When the locking claw 102a is locked to the through-hole H1 of the body panel P during installation of the grommet 101 on the body panel P, the resinous inner member 101 may rotate a little in the direction shown with the circular arrow of FIG. 17.
In the case where the through-hole H1 of the body panel P is elliptical and the peripheral wall of the resinous inner member 101 is also elliptical, the locking claw 4a at the longer side of the resinous inner member 101, orthogonal to the circular arc-shaped locking pieces 102 and 103 at the shorter side, is straight at an outermost edge of the projected portion, as shown in FIG. 18. Thus when the resinous inner member 101 rotates, as shown in FIG. 19A, the locking claw 104a contacts the periphery of the through-hole H1 of the body panel P at a corner C1.
In the case where the locking claw 104a contacts the periphery of the through-hole H1 in this manner, the distance w is long between the periphery of the through-hole H1 and a root portion 104a-2, of the locking claw 104a, which is the final locking position. Thus, there is waste in a pressing amount.
Further since the locking claw 104a contacts the periphery of the through-hole H1 at the corner C1, the force-applied point of the pressing force applied to the locking piece 104 by the periphery of the through-hole H1 is the corner C1. Therefore, the force to flex the locking piece 104 may increase.